Turbidity refers to the cloudiness or haziness of a fluid caused by large quantities of individual particles that are generally invisible to the naked eye, but which can be measured using various types of turbidity sensors. Fluids, such as water, can contain suspended solid matter consisting of particles of many different sizes. While some suspended material will be large enough and heavy enough to settle rapidly to the bottom of the container if a liquid sample is left to stand (the settable solids), very small particles will settle only very slowly or not at all if the sample is regularly agitated or the particles are colloidal. These small, solid particles cause the liquid to appear turbid. Measuring turbidity is a key test of water quality.
Various types of sensors are utilized for turbidity measurement, including those that use an uninterrupted light source or sources and measure the amount of transmitted light or scattered light to determine the turbidity. One issue that occurs with all sensor designs is the presence of bubbles in the fluid stream that is being measured. The diffraction of light through the bubbles distorts the reading, thereby giving an inaccurate turbidity measurement. It would therefore be desirable to provide systems and methods for increasing the accuracy of a turbidity sensor.